1 /* cairo - a vector graphics library with display and print output
2 *
3 * Copyright © 2010 Linaro Limited
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it either under the terms of the GNU Lesser General Public
7 * License version 2.1 as published by the Free Software Foundation
8 * (the "LGPL") or, at your option, under the terms of the Mozilla
9 * Public License Version 1.1 (the "MPL"). If you do not alter this
10 * notice, a recipient may use your version of this file under either
11 * the MPL or the LGPL.
12 *
13 * You should have received a copy of the LGPL along with this library
14 * in the file COPYING-LGPL-2.1; if not, write to the Free Software
15 * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
16 * You should have received a copy of the MPL along with this library
17 * in the file COPYING-MPL-1.1
18 *
19 * The contents of this file are subject to the Mozilla Public License
20 * Version 1.1 (the "License"); you may not use this file except in
21 * compliance with the License. You may obtain a copy of the License at
22 * http://www.mozilla.org/MPL/
23 *
24 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
25 * OF ANY KIND, either express or implied. See the LGPL or the MPL for
26 * the specific language governing rights and limitations.
27 *
28 * Contributor(s):
29 * Alexandros Frantzis <alexandros.frantzis@linaro.org>
30 */
31
32 #include "cairoint.h"
33 #include "cairo-gl-private.h"
34
35 #include <errno.h>
36
37 int
_cairo_gl_get_version(void)38 _cairo_gl_get_version (void)
39 {
40 int major, minor;
41 const char *version = (const char *) glGetString (GL_VERSION);
42 const char *dot = version == NULL ? NULL : strchr (version, '.');
43 const char *major_start = dot;
44
45 /* Sanity check */
46 if (dot == NULL || dot == version || *(dot + 1) == '\0') {
47 major = 0;
48 minor = 0;
49 } else {
50 /* Find the start of the major version in the string */
51 while (major_start > version && *major_start != ' ')
52 --major_start;
53 major = strtol (major_start, NULL, 10);
54 minor = strtol (dot + 1, NULL, 10);
55 }
56
57 return CAIRO_GL_VERSION_ENCODE (major, minor);
58 }
59
60 cairo_gl_flavor_t
_cairo_gl_get_flavor(void)61 _cairo_gl_get_flavor (void)
62 {
63 const char *version = (const char *) glGetString (GL_VERSION);
64 cairo_gl_flavor_t flavor;
65
66 if (version == NULL)
67 flavor = CAIRO_GL_FLAVOR_NONE;
68 else if (strstr (version, "OpenGL ES 3") != NULL)
69 flavor = CAIRO_GL_FLAVOR_ES3;
70 else if (strstr (version, "OpenGL ES 2") != NULL)
71 flavor = CAIRO_GL_FLAVOR_ES2;
72 else
73 flavor = CAIRO_GL_FLAVOR_DESKTOP;
74
75 return flavor;
76 }
77
78 unsigned long
_cairo_gl_get_vbo_size(void)79 _cairo_gl_get_vbo_size (void)
80 {
81 unsigned long vbo_size;
82
83 const char *env = getenv ("CAIRO_GL_VBO_SIZE");
84 if (env == NULL) {
85 vbo_size = CAIRO_GL_VBO_SIZE_DEFAULT;
86 } else {
87 errno = 0;
88 vbo_size = strtol (env, NULL, 10);
89 assert (errno == 0);
90 assert (vbo_size > 0);
91 }
92
93 return vbo_size;
94 }
95
96 cairo_bool_t
_cairo_gl_has_extension(const char * ext)97 _cairo_gl_has_extension (const char *ext)
98 {
99 const char *extensions = (const char *) glGetString (GL_EXTENSIONS);
100 size_t len = strlen (ext);
101 const char *ext_ptr = extensions;
102
103 if (unlikely (ext_ptr == NULL))
104 return 0;
105
106 while ((ext_ptr = strstr (ext_ptr, ext)) != NULL) {
107 if (ext_ptr[len] == ' ' || ext_ptr[len] == '\0')
108 break;
109 ext_ptr += len;
110 }
111
112 return (ext_ptr != NULL);
113 }
114